在 Swift 中使用 WatchConnectivity / 编码传输自定义对象数组

Question

我正在尝试将一组自定义对象从 iOS 传输到 watchkitextension。

了解为了做到这一点，需要对数据进行编码。虽然解码时出错。

我们开始吧：

自定义对象：

    final class Person: NSObject {
        var PersonName:String = ""
        var PersonAge:Int = 0
        var joined:NSDate = NSDate()

        init(PersonName: String, PersonAge:Int, joined:NSDate){
            self.PersonName = PersonName
            self.PersonAge = PersonAge
            self.joined = joined
            super.init()
        }
    }

   extension Person: NSCoding {
        private struct CodingKeys {
            static let PersonName = "PersonName"
            static let PersonAge = "PersonAge"
            static let joined = "joined"
        }

        convenience init(coder aDecoder: NSCoder) {
            let PersonName = aDecoder.decodeObjectForKey(CodingKeys.PersonName) as! String
            let PersonAge = aDecoder.decodeIntForKey(CodingKeys.PersonAge) as! Int
            let joined = aDecoder.decodeDoubleForKey(CodingKeys.joined) as! NSDate

            self.init(PersonName: PersonName, PersonAge: PersonAge, joined: joined)
        }

        func encodeWithCoder(encoder: NSCoder) {
            encoder.encodeObject(PersonName, forKey: CodingKeys.PersonName)
            encoder.encodeObject(PersonAge, forKey: CodingKeys.PersonAge)
            encoder.encodeObject(joined, forKey: CodingKeys.joined)
        }
    }

带有数组的类：

@objc(Group)
final class Group: NSObject {

    static let sharedInstance = Group()

    var Persons:[Person] = []

    required override init() {
        super.init()
    }

    init (Persons:[Person]){
        self.Persons = Persons
        super.init()
    }

}

extension Group: NSCoding {
    private struct CodingKeys {
        static let Persons = "Persons"
    }

    convenience init(coder aDecoder: NSCoder) {

        let Persons = aDecoder.decodeObjectForKey(CodingKeys.Persons) as! [Person]
        self.init(Persons: Persons)

        self.Persons = aDecoder.decodeObjectForKey(CodingKeys.Persons) as! [Person]
    }

    func encodeWithCoder(encoder: NSCoder) {
        encoder.encodeObject(Persons, forKey: CodingKeys.Persons)
    }
}

创建示例对象，附加到数组，然后编码：

let aPerson:Person? = Person(PersonName: "Martin", PersonAge: 50, joined: NSDate())

Group.sharedInstance.Persons.append(aPerson!) 
let encodedData = NSKeyedArchiver.archivedDataWithRootObject(Group.sharedInstance)

在这里我得到错误“执行被中断 - 原因信号 SIGABRT”

let decodedData = NSKeyedUnarchiver.unarchiveObjectWithData(encodedData) as? Group

Answer 1

尝试将这些部分更改为：

convenience init(coder aDecoder: NSCoder) {
    let PersonName = aDecoder.decodeObjectForKey(CodingKeys.PersonName) as! String
    let PersonAge = aDecoder.decodeIntForKey(CodingKeys.PersonAge) as! Int
    let joined = aDecoder.decodeObjectForKey(CodingKeys.joined) as! NSDate

    self.init(PersonName: PersonName, PersonAge: PersonAge, joined: joined)
}

func encodeWithCoder(encoder: NSCoder) {
    encoder.encodeObject(PersonName, forKey: CodingKeys.PersonName)
    encoder.encodeInt(PersonAge, forKey: CodingKeys.PersonAge)
    encoder.encodeObject(joined, forKey: CodingKeys.joined)
}

使序列化与反序列化相匹配，以及 Person 类所需的类型。也就是说，WWDC 关于 WatchConnectivity 的演讲特别推荐不要使用 NSKeyedArchiver，因为它不是一种非常节省空间的序列化方法。